Problem 1 (Required, 25 marks) Mr. A borrows an amount $99000 from the bank today and agrees to repay the loan by 4n level monthly payments made at the end of every month. The first payment is made one month after today. The loan charges interest at an annual nominal interest rate of 11% convertible continuously. It is given that the outstanding balance at (2n)th payment date is 57151.91. (a) Using retrospective method, calculate the outstanding balance at nth payment date. (b) Calculate the principal repaid in (3n)th payment